Rahul Gandhi, the 43-year-old scion of India's most famous political dynasty, has launched the ruling Congress party's campaign for re-election in polls due next spring with a promise to bring in a "young government".

Analysts agree that 120 million first-time voters in India will be crucial in determining if the current coalition, in power since 2004, can win in what is predicted to be a bitter and close contest next year.

Half of Indians are under 26, with an even higher proportion in the big, poor northern states such as Bihar and Uttar Pradesh, where Gandhi addressed large rallies on Wednesday.

Uttar Pradesh, which has poverty levels worse than many parts of sub-Saharan Africa, has the highest number of potential first-time voters in India with 23 million. They will account for almost a fifth of the state's 129 million eligible voters, the Times of India said.

"The first-time voters are very important but it all depends on the ability of the candidates and the parties to motivate them to go out and vote," said Swapan Dasgupta, an Indian political analyst.

Gandhi, vice-president of the Congress party, recently took on the old guard of the organisation, publicly opposing an executive order from the 81-year-old prime minister, Manmohan Singh, which would have allowed politicians convicted of criminal charges to remain in office and stand in elections.

About 30% of Indian lawmakers across federal and state assemblies have criminal charges against them, and following a supreme court order in July many faced being expelled from their seats, including government allies seen as important for electoral success.

The former management consultant and son of Sonia Gandhi, the widow of the assassinated prime minister Rajiv Gandhi and current president of the Congress party, said the order was "nonsense" and called on the cabinet to "tear it up". After some debate, the order was withdrawn.

The main opponent for Gandhi and the Congress party is Narendra Modi, the controversial chief minister of Gujarat state and prime ministerial candidate for the Bharatiya Janata party (BJP), a Hindu nationalist conservative party which held power before being defeated in 2004.

Modi's reputation has been tarnished by allegations that he failed to protect Muslims during sectarian rioting in Gujarat in 2002. He is however popular with the business community and among many urban voters.

"Both parties are attaching much importance to a campaign in tune with the aspirations and cultural mores of young people. The BJP aims to inject a bit of pop culture. The Congress seems to be going back to the 1970s slogans of 'banish poverty'," Dasgupta, the analyst, said.

Gandhi stressed the problems of poor, rural communities – historically the core support of Congress – in Wednesday's rallies but was careful to mention young people.

"In 2014, it will be a poor man's government, a government of youths. We will empower every section of society. I am not scared and there is no one to scare us," Gandhi told one rally in Rampur, 150 miles north-west of Delhi, the capital.

The Congress party hope that a pledge to massively expand India's huge food security subsidy scheme will offset the traditional swing against incumbents.

In another move many say is designed to bolster support before the polls, the Congress-led government last week ordered the division of the southern state of Andhra Pradesh into two, with a new state of Telangana, India's 29th, coming into existence.

However, electricity workers have shut down power plants across Andhra Pradesh in protest, cutting supplies to tens of millions of people and causing chaos. The workers are among thousands of people in Andhra Pradesh who have gone on strike, saying the new state will divide Telugu-speaking people, lead to cuts in the state budget and problems with water resources.

Scores of freight and passenger trains were cancelled. Hospitals and drinking water utilities in the state were operating with generators, while mobile phone services, gas stations and other businesses were also affected.

On Wednesday Digvijaya Singh, a senior Congress party official who is close to Rahul Gandhi, said the decision to create Telangana would not be reversed.